The present invention relates to a fuel cell.
A fuel cell is provided with a fuel cell stack having a stacked structure in which a plurality of unit cells of the fuel cell are stacked, where each unit cell generates power. In the fuel cell stack, terminal plates which function as power collectors are provided to be joined to the unit cells located at ends of the fuel cell stack, and insulating plates are further provided outside the terminal plates. The fuel cell is provided with a gas supply manifold and a gas discharge manifold which extend in cell stacking directions so that they penetrate the fuel cell stack, and the terminal plates and the insulating plates which were joined to the ends of the fuel cell stack. Each unit cell of the fuel cell is supplied with gas from the gas supply manifold, and discharges off-gas to the gas discharge manifold. The off-gas collected in the gas discharge manifold is discharged outside the insulating plate via the gas discharge manifold which is also formed in the terminal plates and the insulating plates. Reactive gas such as hydrogen gas, as well as oxygen containing gas such as air, are supplied to the unit cells, and moisture may be contained in each off-gas discharged from the unit cells. More specifically, the off-gas of the reactive gas may contain condensate which is formed from steam blended for humidification and produced water which penetrated an electrolyte membrane, and the off-gas of the air may contain the produced water. If the water contained in the off-gas remains inside the manifold, a flow (discharging) of gas may be blocked by frozen moisture. Therefore, JP2009-158338A proposes a technique to discharge moisture by inclining the gas discharge manifold downwardly toward a discharging direction.
According to the technique proposed in JP2009-158338A, since a fuel cell stack which is formed by stacking unit cells is inclined with respect to the horizontal direction, corresponding to the inclination of the gas discharge manifold, the fuel cell stack has different heights in the vertical direction at one end side and the other end side thereof. Thus, for example, when the fuel cell is mounted on a vehicle, a mounting space must be secured and an interference of the fuel cell with peripheral devices must be avoided, taking the height difference in the vertical direction in consideration, and thereby a mounting design is limited. For this reason, a structure in which the moisture remaining in the gas discharge manifold is reduced while securing flexibility of the mounting design is now demanded.